Hollow blast grate bar



June 9, 1925. 1,541,012

P. J. A. VAN DEINSE HOLLOW BLAST GRATE BAR Filed 001'. 31. 1922 3 Sheets-Shoot 1 INVENTOR WITNESSES ATTORNEY June 9, 1925.

P. J. A. VAN DEINSE HOLLOW BLAST Filed Oct; 31. 1922 .3, SheetsSheet 2 WITNESSES June 9, 1925. 1,541,012

P. J. A. VAN DEINSE HOLLOW BLAST GRATE BAR Filed on. 31. 1922 3 Sheets-Sheet 3 Y as I 36 13 ZJAyanDeime WWQ 39 z it I I I b 4 a I I,

ATTOR N BY 4 broken away Patented June 9, 1925.

UNITED STATES PATENT OFFICE.

HOLLOW BLAST GRATE BAR.

Application filed fictooer 31, 1922. Serial No. 598,162.

To all whom it may concern.-

Be it known that I, PAULUs J. A. VAN DEINSE, a citizen of the siding at Greenville, in the county of Montcalm and State of Michigan, have invented a new and useful Improvement in Hollow Blast Grate Bars, of which the following is is a specification.

This invention relates to improvements in hollow blast grates and particularly to the tuyeres thereof.

The invention is particularly applicable to hollow blast grate bars employed in furnaces for burning sawdust, wood refuse, sugar cane refuse, rice chaff and other similar fuels. 1

The general objects of the invention are to provide improved tuyeres which will deliver a maximum volume of the blast to the furnace, which will have no effect of weakening the grate bars, and which will not permit the fuel crashes to accumulate in the chamber of the hollow grate bar.

Other objects will appear from the following description of two embodiments of the invention.

In the accompanying drawing forming a part of this specification:

Figure 1 is a perspective view with parts showing a boiler furnace equipped with one form of the invention;

Figure 2 is a top plan view of one of the hollow grate bars;

Figure 3 is a vertical longitudinal section on the line 3-3 of Figure 2;

Figure 4 is a vertical transverse section on the line 44 of Figure 2;

Figure 5 is a side elevation of one of the tuyere parts;

Figure 6 is a bottom plan view of'the same; j

Figure 7 is a side elevation of the tuyere element which is complemental'to the part shown in Figure 5;

Figure 8 is bottom plan view of the same;

Figure 9 is a sectional view on the line 9 -9 of Figures 6 and 8, the twoparts being shown assembled;

Figure 10 is a similarview on the line 10 10; i

Figure 11 is a similar view on the line 11-11;

Figure 12 is a cross section on the line 12-12 of Figure 6 1 Figure 13 is a cross section on the line 13l3'of Figure 6;

United States, re-

Figures 14 and 15 are perspective views of the two parts of a modified tuyere; and

Figure 16. is a tion of a hollow blast grate bar equipped with the tuyere parts illustrated in Figures 14 and 15.. v r I Referring more specifically to the preferred embodiments of the invention shown in the drawing for illustrative purposes, and first particularly to Figure 1, the boiler furnace 16 is provided with a grate including ordinary draft bars 17 alternating with hollow blast grate bars 18 as shown, the grate bars extending from front to rear' ofthe fire box. Associated with the furnace is a blower 19, whose outlet is joined to an elbow 20. The elbow 20 is connected with a pipe section 21, and to the other end of the pipe section is joined a T consisting of a'horizontal part 22 and a vertical part or nipple, the latter receiving the lower end of a vertical pipe 23. Several pipe sections 21 and Ts 22 are joined in alternation to form a delivery pipe for the blast extendingtransversely of the furnace beneath the grate, as shown; The upper end of each vertical pipe 23 is connected with one of the hollow blast grate bars so that theblast from the blower 119is distributed uniformly to all the grate bars 18. A gate valve or slide 24 provides convenient means for controlling the blast. The arrangement of parts so far described is well known and forms no part of my invention.

driven by any suitable means,

perspective view of a por- The construction of the hollow blast grate tuyere parts are pro- 8 vided, each of said seats of the grate bar is hollow as indicated at 27, and the vertical pipes 23 are joined to depending coupling members 28 preferably integral'with the grate bars, so that the blast from the fan passes through the chamber 27 and out through the tuyere openings. "Preferably at the forward end of each grate bar 18 and upon the lower side thereof a blow-out passage 29 is provided, which is controlled by a slide 30, whereby any dirt or refuse collecting in the chamber 27 may be blown out from time to time. 1

Supported by the surfaces 25 and 26 of the grate bar are annular tuyere elements 31, each of which in turn carries a tuyere ele ment 32, the two elements 31 and 32 together making up a duplex tuyere unit Whose construction is one of the principal features of my invention. For a clearunderstafi'ding of the du alextuyere unit, Figures. 5 to 13 inclusive should be referred to. The 'annula'r outer 'tu'yere member 31, best'shown in Figures 5 and 6, is preferably made "of a single piece of cast iron or similar material. At the upper part of the 'i'n'e niber 31 is anannularbeveled surface, t'he angle of which preferably corresponds with the angle or slope of the seats 25 provided in the grate bar. At intervals about the periphery of the member 31 radi- -al projections "35 and 36 are provided, and the outer end surfaces of all the radial projections are curved longitudinally in conformit'y with the annular shape of the tuyere member and are beveled transversely, so that the members 31 are supported vii-tin 'in the holes provided in the grate bars pref- 'erably having their upper surfaces someiv'hat below the upper s'urfaceof the grate bar. The radial projections 35 and 36 are preferably arranged in alternation and spaced equally about'the periphery of the member 31. Each projection'36 has a seating extension 37 integral therewith and depending therefrom. Preferably the ividth 'of 'the projections 36, fco'mbined with the Widthfof' the ex'tens'i'o'ns 37 is somewhat less than the depth of the seats provided by 'the bevel "surfaces 25, so that "When-the lower endsoffthe extensions'37 "rest'upon the ledge 26, assliow'n in Figure 1'1,"the u er-sun 'face of the tuyere is "slightly iewerthan the upper surface of the grate bar. Beneath some of the projections 35, 36, a "Wing 3811; provided, and the Win-gs 38 extend to the bottom of the tuyere member 31 and have their "outer surfaces curved so that the wings may extend through the holes providedin the upper sides offthe grate bars; as seen in Figures 12 and The objectof the wings -is to prevent displacementof the tuyere parts during the firing operation I From What has been described. it will be understood'that the compressed air delivered to the interior 27 of the hoilow"'grate bars may issue from the passageways provided betweenadjacent radial projections 35 and 36-; and as \vill'be understood from Figure 2, these passageways are relatively long and narrow, so'that there is practicallyno tendency. during the operation 'of the furnace for the fuel to clog the bpenings to prevent the blast of air fromissuing out of the passageways.

The central opening 39 of each annular tuyere member 31 has abevcled seat 10 and a circular ledge 11 corresponding respectively to the seating surfaces 25 and 26 of the grate bar. The tuy'ei'e member 32 is preferably made of cast iron and has integral radial projections 42 and 43 analogous respectively 'to the projections 35 and 36 pre viously described. Each projection 1-3 has a seating extension 13; and ivings 4st proj'ect radially from the member 32 and are passed through'the lower part of the hole or bore provided in each annular tuyere member 31 so as to prevent displacement of member 32. The 'tuyere element is supported by engagement of the seating extensions 43 with the ledge 41. so that its u per surface is preferably somewhat below the upper surface of tu \'*ere 'meni'ber 31, which in turn is preferably somewhat lower than the upper surface of the hollow grate bar. A plurality of narrow passageirays for the blast of air are provided between adjacentprojections 42 and '43. The lower part of the inner tuyere member 32 is enlai-ged'and made ofsor'neivhat bulbous shape asshoivn 'anddepends beloiv the outer tuyere member which adds 'to the \YGiQhi; an'dp'r'events displacement. In other Words, the Weight o'f'th'e inn'er "member assists in hold 'the outer member-in place.

The improved duplex tu'yeie of my invention has two circularsets or series of holes or passageways for the "air blast arranged concentrically. Obviously the blast issuing from each tuyere may be varied by substituting 'tuyer'e elements having a greater or lesser number of passages than 'those shown in the drawing. 'It'isalso clear that the exact shape "and size of the air passages may be varied in differenttuyere units. I i

Each "of the grate bars 18 supports any desired number of the 'tu'yer'es, all of "which arealikeexeept thatatthe front end of each grate bar the foremost'tuyeresconsistingof parts'33"and3 1'areso shaped that the blast is directed through only the rear half-of the castings, as will be understood from Figure 2, so that no part of the fireis forced against. the furnace door. 1

A modified form "of the invention is shown in Figures 14, 15 and 16 wherein the hollow 'grate bar 18 is provided with a plurality of rectangular openings or :perforations having inclined'ituyem seats 4-5. The outer tuyere element 16"hasa central rectangular slanting or beveled seat 47 designed to support the inner tuyere member 50=shownseparately'in Figure 15. Atregular intervals about the four sides of the outer member 46, passa eways i8, 49 are provided so that the blastbfair from the interior of the grate bar may 'pass upwardly into the fire box of the furnace. The in- Figures 14 to 16 inclusive are in general H the same, and the results obtained by the use of either construction are similar, the essential difference being that in one case the tuyere members are circular while in the othercase they are rectangular.

Some of the advantages of the invention are that ashes and fine particles of fuel entering the tuyere settle only upon the ledges 26, ll, from which they are quickly expelled by the blast. Again, if the plant remains idle for any length of time, rust and scale will gather in the outlets of an ordinary blast grate bar and obstruct them; while with my invention the tuyeres can be readily removed, the outlets cleaned and the tuyeres replaced. Sometimes it is discovered that the grate bar outlets originally provided are too large or too small, due either to an error in calculation or to a change in fuel- My invention provides means whereby the size of the outlets may be increased or reduced temporarily or permanently to any extent desired and as often as may be necessary.

The tuyeres of my invention being held in place solely by their own weight, they are readily removed to give access to the interior of the grate bar. For this reason and the further reason that a minimum of ashes, etc., finds its way into the interior of the bar, the blow-out in the front end thereof need be used only on very rare occasions, or may be dispensed with altogether. On the other hand, when wet sawdust or other matter containing a large percentage of moisture is burned on a hollow blast grate bar without gravity tuyeres, the ashes entering the interior of the bar becomes moist and cakes, requiring it to be dug out manually-an operation of considerable difliculty and taking considerable time, as the bar must usually be removed from the furnace for the purpose.

The invention greatly increases the area. of the blast outlets without adding to the number of the tuyere seats in the top of the grate bar, which would weaken the grate bar and permit it to sag, and at the same time the openings do not become obstructed by the fuel, as has already been pointed out.

While I have described two preferred embodiments of the invention, it will be understood that many changes may be made from the above, without departing from my invention, which is best defined in the following claims.

In practice, I may combine a circular tuyere member with a rectangular tuyere member by arranging the circular member either on the outside or Within the rectangular member, thereby making four differthe grate bar at cut combinations; or I may make either.

tuyere member of any other desired shape.

lVhat is claimed is 1. A hollow blast grate bar having an opening on its upper side leading from the interior thereof, in combination with a tuyere adapted to be seated in'and partially close said opening, said tuyere being made up of two elements having air passages, one element seated on the wall of said opening and the other element seated on the firstinentioned element so that its upper surface is below the surface of the grate bar, both elements "being held in position by gravity. V

2. A hollow blast grate bar having an opening on its upper side communicating with its interior, and atuyere seated upon said opening with its upper flat surface disposed lowerthan the upper surface of the grate bar, said tuyere being held in position solely by gravity, and comprising two tuyere elements, one of which seats the other and'is in turn seated within said opening.

3. In combination with a hollow blast grate bar having an opening providing a seat in one side, a tuyere element having a plurality of passages for air as well as a central aperture, said aperture providing a seat for a second tuyere element likewise provided with air passages, both seats and the seating surfaces of both elements being formed similarly, and the second tuyere element being provided with a depending weighted enlargement to hold both tuyere elements on their seats solely by gravity.

4. A hollow blast grate bar having an opening on its upper side leading from the interior thereof, in combination with a close-said opening, said tuyere being made up of two elements each having air passages, the outer element being seated on the wall of said opening below the upper surface of the grate bar,and the inner element being seated on the first-mentioned element below the upper surface of the outer element and provided with a weighted enlargement depending below the other element, whereby both elements are held in position by gravity.

5. A hollow blast grate bar having an opening in its upper Wall leading from the interior thereof, said opening having an inclined surface and a flat horizontal ledge below the top face of said upper wall, and a tuyere element fitted in said opening having a series of spaced projections at the periphery engaging said inclined surface, air passages being provided between adjacent projections certain of the projections having a depending seating extension to rest upon the ledge, wings provided on certain of the projections and extending to the i tuyere adapted to be seated in and partially bottom "of the tuyere element, =said tuyere element having a central opening With a beveled seat and a fiat horizontal ledge he-- lOW the top face thereof, and a second tuyere element fitted insaid central opening having radial projections at the periphery engaging said beveled seat, air passages 'being provided between adjacent projections, "cerain of said projections having extensions resting on the last-mentioned ledge.

6. A hollow hlast grate loar having an opening in its upper Wall leading from the interior thereof, said opening having an inclined surface and a flat horizontal ledge below the top face of said upper wallga'nd a tuyere element fitted in said. opening havaseries of spaced projections at the periphery engaging said inclined surface,- air passages being provided between adjacent F' projections, certain of the projections having depending seating extension to rest upon the ledge, Wings provided on certain of the projections and extending to the -bot tom of the tuyere element, said tuyere element having a central opening with a beveled seat and a fiat horizontal ledge below the top face thereof, and a second tuyere element fitted in said central opening having radial projections at the periphery engaging said beveled seat, air passagesbeing provided between adjacent projectionscerlain of said projections having extensions resting on the last-mentioned ledge, thesec- 0nd tuyere element being Weighted and serving to hold both elements onto their seats solely by gravity. I

In testimony that I claim the foregoing as my own, I have hereto atfixed my signature.

PAULUS J. A. VAN DEINSE. 

